feat: expose skills/ to pi coding agent via package.json pi.skills field

[c-99-e]

Context

@playwright/cli already ships a complete skill at skills/playwright-cli/SKILL.md (with full reference docs for mocking, tracing, video, sessions, test generation), and the install --skills command installs it for Claude Code.

However, the pi coding agent discovers skills from npm/git packages via a pi.skills field in package.json — part of the vendor-agnostic Agent Skills standard. Without it, pi users can't auto-discover the skill when they install @playwright/cli.

Related: #294 and #299 discuss the .agents/skills/ standard for project-level discovery. This issue is specifically about package-level discovery when installed via pi.

Fix

A one-line addition to package.json pointing at the existing skills/ directory:

"pi": {
  "skills": ["./skills/"]
}

PR: #305

Workaround

Until merged, pi-playwright-cli bundles the skill and installs @playwright/cli automatically:

pi install git:github.com/c-99-e/pi-playwright-cli

[c-99-e]

Closing this — turns out pi's auto-discovery already finds the skills/ directory when installing via pi install git:github.com/microsoft/playwright-cli. No package.json change needed.